This is a proposal to conduct a case-control study to determine exposures that predispose a person to the development of condylomata acuminata (warts on the genital or perianal region caused by infection with human papilloma virus), as well as to determine those exposures that may reduce the risk of genital warts. A knowledge of risk factors for condyloma acuminatum is of importance because there is accumulating evidence that the presence of human papilloma virus (HPV) strongly predisposes to the occurrence of cancer at several sites. We plan to identify and interview the approximately 800 men and women who are diagnosed as having condyloma between October 1, 1986 and September 30, 1991 at three clinics of the Group Health Cooperative of Puget Sound (GHC). To estimate the exposures of men and women in this population to various potential etiologic factors, a sample of approximately 900 demographically-comparable men and women from the GHC membership file that serves these clinics will be identified and interviewed as well. Exposures of special interest include long- term use of oral contraceptives in women, homosexual behavior in men, smoking (cigarettes and marijuana), barrier methods of contraception, and nutrition in both men and women. In order to obtain an estimate of the distribution of the different types of HPV in a defined population and to determine how these types relate to the risk factors and anatomical sites, all condylomata treated at one clinic (250 patients) will be biopsied and typed for HPV. Blood samples will also be collected from these patients and their controls. These samples will be tested for serum antibody to sexually transmitted diseases. Additional sera will be frozen for future determination of papillomavirus antibodies.